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WASHINGTON, D.C. -- Search and rescue operations at the DeBruce Grain Co. elevator in Haysville, KS, were temporarily suspended last night after support shoring gave way, allowing grain to spill into a tunnel where rescuers are looking for a missing worker.

The shoring was used to prop up a damaged hatch on the bottom of a huge grain bin full of millet. Rescuers in the area experienced no injuries or entrapment at the time of the incident. Operations resumed a short time later following re-shoring and an inspection by safety officers.

Members of Urban Search & Rescue Task Force One-Nebraska, along with local responders, returned to the scene to search for the fourth missing worker in an 800-foot-long tunnel running underneath the massive grain bins. Rescuers have searched approximately 75 percent of the tunnel.

The 64-member task force is working in three shifts over a 24-hour period. They are supported by a 21-member support team at the site and a disaster field office in nearby Wichita.

The death toll stands at five. Additional fragments of human remains have been found. Identity of the remains is awaiting determination by the county coroner.

As the search entered its 85th hour, local emergency service officials remain publicly optimistic that the rescuers will find the fourth man alive. Local Fire Chief Gary Curmode said he's hopeful because of the way most grain elevators are built. A typical tunnel underneath a grain elevator has a few small rooms built into its walls, he said. The missing worker could have survived the blast if he was in one of those little rooms at the time of the explosion, the chief said.